JP-A-09-101361 discloses an FM-CW radar that enables plural targets to be detected in the mobile radar mounted on an automobile or the like.
Also, JP-A-2007-240313 discloses an azimuth angle detecting device that executes a space average detecting process when a velocity of a subject vehicle is equal to or lower than a threshold value, and detects the azimuth angle of each target that generates a reflected wave of a radar wave received by a receiving antenna.
Further, Kagaku Gijutsu Shuppan Inc., Nobuyoshi Kikuma, “Adaptive signal processing Utilizing array antennas”, 1998, p. 174 (herein after “Kikuma”), and JP-A-2003-270316 disclose a super-resolution method that detects an azimuth orientation of an obstacle by using an antenna radiation pattern combining the directivities together after the weighting of the amplitude/phase of the respective receiving antennas has been controlled with the use of plural receiving antennas.